package com.tianji.learning.service.impl;

import cn.hutool.core.util.ObjectUtil;
import com.tianji.common.autoconfigure.mq.RabbitMqHelper;
import com.tianji.common.exceptions.BizIllegalException;
import com.tianji.common.utils.BooleanUtils;
import com.tianji.common.utils.UserContext;
import com.tianji.learning.domain.vo.SignResultVO;
import com.tianji.learning.mq.message.SignMessage;
import com.tianji.learning.service.SignRecordService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.data.redis.connection.BitFieldSubCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.time.LocalDate;
import java.util.List;

import static com.tianji.common.constants.MqConstants.Exchange.LEARNING_EXCHANGE;
import static com.tianji.common.constants.MqConstants.Key.SIGN_IN;
import static com.tianji.common.utils.DateUtils.DATE_SUFFIX_FORMATTER;
import static com.tianji.learning.constants.RedisConstants.SGIN_RECORD_KEY_PREFIX;

/**
 * <p>
 * 学习积分记录，每个月底清零 服务实现类
 * </p>
 *
 * @author 东哥
 * @since 2024-06-29
 */
@Slf4j
@Service
@RequiredArgsConstructor
public class SignRecordServiceImpl implements SignRecordService {
    private final StringRedisTemplate redisTemplate;
    private final RabbitMqHelper mqHelper;

    /**
     * 1、添加签到记录（Day7 - 课堂）
     *
     * @return
     */
    @Override
    public SignResultVO addSignRecord() {
        // 1、签到
        // 1.1、获取当前登录用户
        Long userId = UserContext.getUser();

        // 1.2、获取当前日期
        LocalDate now = LocalDate.now();
        String dateStr = now.format(DATE_SUFFIX_FORMATTER);

        // 1.3、拼接key
        String key = SGIN_RECORD_KEY_PREFIX + userId + dateStr;

        // 1.4、计算offset值
        int offset = now.getDayOfMonth() - 1;

        //1.5、签到并校验是否是重复签到（核心）
        Boolean exists = redisTemplate.opsForValue().setBit(key, offset, true);
        if (BooleanUtils.isTrue(exists)) {
            throw new BizIllegalException("不允许重复签到！");
        }

        // 2、计算连续签到天数
        int days = countSignDays(key, now.getDayOfMonth());

        // 3、计算签到奖励积分
        int rewardPoints = computePoints(days);

        // 4、封装vo
        SignResultVO vo = new SignResultVO();
        vo.setSignDays(days);
        vo.setRewardPoints(rewardPoints);

        // 5、保存积分明细记录（发送MQ消息）
        try {
            mqHelper.send(LEARNING_EXCHANGE, SIGN_IN, SignMessage.of(userId, vo.totalPoints()));
        } catch (Exception e) {
            log.error("签到发送新增积分消息失败：{}",e);
        }

        return vo;
    }

    /**
     * 计算连续签到奖励积分
     *
     * @param days
     * @return
     */
    private int computePoints(int days) {
        switch (days) {
            case 7:
                return 10;
            case 14:
                return 20;
            case 28:
                return 40;
            default:
                return 0;
        }
    }

    /**
     * 2、查询签到记录（Day7 - 课堂）
     *
     * @return
     */
    @Override
    public Byte[] querySignRecords() {
        // 1、获取key
        // 1.1、获取当前登录用户
        Long userId = UserContext.getUser();

        // 1.2、获取当前日期
        LocalDate now = LocalDate.now();
        String dateStr = now.format(DATE_SUFFIX_FORMATTER);

        // 1.3、拼接key
        String key = SGIN_RECORD_KEY_PREFIX + userId + dateStr;

        // 2、查询截止到当天的签到记录
        int dayOfMonth = now.getDayOfMonth();
        List<Long> result = redisTemplate.opsForValue()
                .bitField(key,
                        BitFieldSubCommands.create().get(BitFieldSubCommands.BitFieldType.unsigned(dayOfMonth)).valueAt(0)
                );
        if (ObjectUtil.isEmpty(result)) {
            return new Byte[]{};
        }
        int signResult = result.get(0).intValue();

        // 3、循环每一天的签到情况，赋值给byte数组
        Byte[] arr = new Byte[dayOfMonth];

        int pos = dayOfMonth - 1;
        while (pos >= 0) {
            arr[pos--] = (byte) (signResult & 1);
            signResult >>>= 1;
        }

        return arr;
    }

    /**
     * 计算连续签到天数
     *
     * @param key
     * @param dayOfMonth 当天在当月是第几天
     * @return
     */
    private int countSignDays(String key, int dayOfMonth) {
        // 1、通过bitfield命令获取本月从第一天到今天为止的所有签到记录
        List<Long> result = redisTemplate.opsForValue()
                .bitField(key,
                        BitFieldSubCommands.create().get(BitFieldSubCommands.BitFieldType.unsigned(dayOfMonth)).valueAt(0)
                );
        if (ObjectUtil.isEmpty(result)) {
            return 0;
        }
        int signResult = result.get(0).intValue();

        // 2、定义一个计数器
        int days = 0;

        // 3、用签到查询结果不断跟1进行与运算，并且判断是否等于1
        while ((signResult & 1) == 1) {
            // 连续签到天数 + 1
            days++;
            // 签到查询结果无符号右移一位
            signResult >>>= 1;
        }

        //4、返回连续签到天数
        return days;
    }
}
